Modeling the Impact of Rain and Clouds on Earth–Space Site Diversity Systems

A statistical model to predict the effects of both rain and clouds on the earth-space site diversity communication systems is presented. The methodology relies on the assumption, already widely considered in the literature, that both rain- and cloud-induced attenuations can be separately modeled, both in space and time, using log-normal distributions. The model is preliminarily tested against joint statistics of rain and cloud attenuations derived from the propagation data set collected in three Italian sites (Spino d'Adda and Milan, in the North, and Tito Scalo, in the South) during the ongoing Alphasat Aldo Paraboni propagation experiment. Although additional experimental data including attenuation induced by rain and clouds are required to further assess the accuracy of the proposed site diversity model, the obtained results, both for short (~20 km) and large (~760 km) site separation distances, are definitely encouraging and suggest that the proposed model is a step towards providing a more comprehensive and accurate prediction of tropospheric impairments for near future high-frequency earth-space systems implementing the site diversity.